To fixedly secure two components together as a single unit, and particularly when the components must be capable of supporting and transmitting significant torque loads, a permanent interference fit is often created between an interior diameter of one part and a corresponding exterior diameter of a mating part to create a secure and permanently rigid connection between component parts. In some instances the components are adapted to rotate together as a single unit.
The components, for example a metal sleeve and a metal shaft to which the sleeve is to be mated, may be provided such that the metal sleeve is formed of a harder metal, for example steel, than the metal of the shaft, as, for example, aluminum. In such cases, for example, a hardened steel sleeve may be formed with axially extending splines, while the aluminum shaft may have a smooth exterior surface adapted to receive the interiorly splined sleeve. In such cases, the interior diameter of the sleeve and respective exterior diameter of the shaft are closely sized to achieve desired interference.
Those skilled in the art will appreciate that the hardened metal splines of the sleeve are adapted to cut into the softer metal exterior diameter of the shaft to create an interference fit. During actual assembly of the two parts, the splines of the sleeve will generate chip debris as the splines cut into the softer metal exterior of the shaft. To accommodate the chip debris, the axially extending splines of the sleeve may be intersected by a circumferential groove adapted to receive the chips, as well as to provide at least one cutting-edge for cutting into the shaft. The latter action generates the chip debris.
The particular groove design as conventionally employed may give rise to distortion of the outside geometry and/or shape of the outer component, i.e. the sleeve, due to inability of the sleeve to accommodate chip debris along a substantial portion of the interference fit between the parts. Such lack of means to accommodate chip debris may create actual distortion of the sleeve, which may be particularly undesirable in situations where such distortion may impact critical exterior sleeve tolerances.